Energy efficient recovery of acrylonitrile

Claim 1

In the process for the recovery and purification of acrylonitrile from an aqueous solution of acrylonitrile, acetonitrile, HCN and impurities consisting of the steps of: (a) distilling said aqueous solution in an extractive distillation column with solvent water to produce an overhead stream of acrylonitrile, HCN and water, and a bottoms stream of water and impurities; (b) distilling in a second distillation column the overhead stream of (a) to produce a second overhead stream of HCN and water, and a second bottoms stream of acrylonitrile and impurities; (c) distilling in a product column the second bottoms stream of (b) to recover product quality acrylonitrile, the improvement comprising; passing said bottoms stream of (a) in indirect heat exchange relationship with liquid from the second distillation column of (b) followed by the liquid from the product column of (c) to provide heat to the respective columns.